This is certainly a disappointment in the fight against global AIDS. As a sidelight,these kinds of studies always make me wonder what kind of people(in this case 3000) volunteer to get infected with the AIDS virus. It would be interesting to interview such people...

A much-heralded H.I.V. vaccine has failed to work in a large clinical trial, dealing another serious setback to efforts to stop the AIDS epidemic. The vaccine’s developer, Merck, said yesterday that it had halted test vaccinations after the vaccine failed to prevent infection or reduce the severity of infection among volunteers who became infected during the trial.